Nothing I Wouldn't Do
by seemeinacrown
Summary: It's been three years since Dean has lived in the same house as Sam. Living with his boyfriend Cas, it's much easier to keep his wanton fantasies of his little brother under control. But one night Sam calls Dean, desperate and hurt, Dean and his boyfriend take him in temporarily, and things become much more complicated than Dean ever really intended them to be.
1. Chapter 1

Dean's fucked up, and he knows it. So, so wrong. But he almost likes it, in a way. And he sure as hell isn't gonna fight it. Because nothing feels better than envisioning his little brother under him, moaning and writhing and calling out _his_ name while Dean finishes alone in his room, and he can't imagine how much better it would feel in real life. His baby brother, sprawled out for him, begging for him, being good for him…his fucking baby brother. Sammy. But he knows it's wrong, so he always cleans himself up and then drives over to Cas' house to eat the son of a bitch out.

He met Cas the summer after high school graduation, working in an auto shop, when the rich bastard stopped by to get his BMW checked out. Dean had handed the job over to the shop owner and spent the next twenty minutes flirting with Cas while his car was getting checked out in the garage. Cas was 23 and damn near perfect. Brown, wild hair, dangerous eyes, ass that jutted out in all the right ways, and a smile that could literally charm the pants off someone. Luckily, Dean had always looked older than his age and had the guy agreeing to take Dean home with him in ten minutes flat. So once the owner had come back and told Cas he'd have to order a part and that he'd call him when it was in, Dean fed Mr. Jeppson some shit about having to run home because Sammy was hurt, hopped in his old Impala, and followed the stranger to his apartment. It never crossed Dean's mind to be wary because sex was sex and you didn't pass up an opportunity with a man like this, where the possible rewards far outweighed the risks.

They'd spent the four hours sweating and biting and grabbing and scratching and _fucking_ , oh, fucking. Dean had never been so satisfied in his life, and he was delirious with pleasure when they'd finally laid down next to each other and called it quits. Dean had rolled over, feeding Cas with some bullshit line about how Cas had been much better than Dean could've imagined in the fifteen prior minutes they'd known each other and Cas had laughed, kissing Dean affectionately and nuzzling the younger boy. It felt safe in that bed, dirty and sweaty and hot and strange, still, but safe, and Dean knew it wouldn't be easy letting it go. And he didn't have to, in the end. A spontaneous afternoon together turned into days took off work and sneaking out and regular, casual fucking, but after a while that turned to cuddling and beer and watching football games, and it wasn't long before that became a full-fledged relationship. Dean wasn't the type to stay long-term, but Cas had filled his sexual needs, and, more importantly, distracted him from the thoughts of Sammy that drove him crazy and sick more often than he liked. Besides, he'd actually come to love the man over the months and years, and even if this had started as a sick, coping-mechanism joke, it was too late to back out now, and Cas was his. There were worse things than having a loaded boyfriend to come home to at night.

Dean was twenty-two now, working in the same garage and taking night classes twice a week, while Cas spent his days as a financial analyst at a firm downtown. Dean couldn't process half the things Cas said when he came home and Dean asked him how work had gone, but he liked the way his boyfriend's eyes lit up as he talked sometime he loved and understood, even if his face was weary and crestfallen from a long day. He really was fucking beautiful.

He looked up from the dishes he was doing when he heard their door unlatch.

"Honey, I'm home," Cas called, smirking as he waltzed into the kitchen and backed Dean against a counter.

"Don't get all domestic with me, _sweetheart_ ," Dean shot back, kissing the older man gently.

"Mmmm, mmmm, fine." Cas bit his lip and traced his fingertips alone Dean's shirt collar, then his chest, then his hips. "Miss me?"

Dean laughed and shot his boyfriend a wicked look. "Oh, you fuckin' know it."

They were undressed and Dean was up on the counter before they both knew it, desperately clawing at each other and bucking their hips. Things weren't always so rough when they were having sex—initially, it had been—but once in a while they got just as eager and uncontrollable as they'd been when they'd first met, and left each other bruised and scratched as kids who'd gotten in a fight after school. To be honest, Dean liked this a lot more than the sweet, gentle sex they'd have in bed, but he didn't have the heart to tell Cas that—and besides, that sex was good too. Just different.

Cas had just started working his mouth around Dean's cock when Dean's phone rang, startling Dean but not the older man.

"Wanna get that?" Cas looked up with honest questioning, something Dean absolutely adored about his partner. He was fully committed to their sex, but if something came up, even right in the middle of it, Cas was always ok with stopping, no questions asked, no complaints.

Dean shook his head and was about to buck his hips back towards Cas' head when Cas grabbed Dean's phone off the counter and held it out to him.

"It's your brother." Dean's eyebrows furrowed in worry for a moment before he shrugged it off. "You sure? Dean, I really won't be offended, and if it's not a big deal, you can ask him to call back later. Ok, baby?"

Dean sighed and took the phone. He cared about Sammy more than anything in the world, but he hadn't talked to the kid on the phone for a month and he was doing alright, not having fantasies about him, and he didn't want to open that back up. "Sammy?"

"Dean." Dean could immediately sense the tears and fear in Sam's voice.

"Sammy, what's wrong?" Dean hopped off the counter, walking into the other room.

"Dee—Dean, it's dad."

 _Shit fuck_. "What the fuck did he do to you, Sammy?"

Sam sobbed heavily before reply. "He…it was really bad, Dean. Real bad."

"Sammy, what did he do to you?" Dean growled.

"I—I'm not entirely sure, but it hurts Dean, hurts real bad, and I'm bleeding-."

"Where are you?" Dean held the phone between his shoulder and chin as he walked back into the kitchen and started to redress.

"I'm in the bathroom at the Maverick by the grocery story. The one a block from home." Dean could hear the boy shivering and sobbing.

"Listen, you stay in that bathroom, you hear? Don't leave, I'll be there in fifteen, ten minutes. I'll call you when I get there, and call me if anything happens, but you stay there, understand?"

"Yes Dean."

"Good." Dean hung up and threw on his shirt and searched for his keys on the floor.

"Is everything ok?" Cas touched Dean's face and looked at him with concern.

"No, fuck—I'm so sorry, Cas."

"No, no, don't babe, please. Do you want me to come with you?"

Dean considered. Normally he'd say no, figure Sam wanted space, but it sounded like Sam was pretty banged up and Dean might need some help with the kid in the car. "Yes. Please."

"Of course." Cas dressed quickly and followed Dean out to their car.

"Is there still a blanket in the back of the car?"

Cas nodded as Dean pulled out of the apartment's lot. "Yeah, there is. Can I ask what happened? You don't have to tell me, either, none of my business." Cas reached across the car to grab Dean's hand, who grabbed back gratefully.

"Old man got him pretty bad, sounds like."

"I'm so sorry, Dean."

Dean nodded a silent acknowledgment and accelerated. His and Cas' place was only a fifteen minute drive from where Sam was, but that still seemed too long knowing his little brother, his baby, baby brother was standing broken and scared in a gas station restroom.


	2. Chapter 2

Dean ran into the Maverick as soon as he'd put the car in park, leaving it running and Cas sitting in the front seat. He called Sam as he burst through the front doors, but he'd made his way to the bathroom and pushed in before the phone had even rang twice.

"Sammy?"

"Dean?" Sam pushed open a stall door and threw himself into his brother's arms. "Dean."

Dean immediately grabbed his brother back and held him close, kissing his head and smoothing his hair. "Shhhh, it's ok Sammy. I've got you, I've got you."

Sam sobbed into Dean's shoulder; he was almost taller than Dean now, but he seemed a lot smaller like this, and Dean practically had to hold up the kid as he cried. It was fucking hard seeing his eighteen year old brother broken down and sobbing just like he was five years old and scared again, and Dean swallowed the urge to cry himself. After a few minutes, Sam pulled back.

"Baby boy, shit, you're all beat up." 'Beat up' was an understatement. Dean grimaced as he surveyed his younger brother. There was a gash on his forehead that looked like it had been gushing blood at one point, one eye was almost swollen shut, and other cuts littered Sam's face. And that was just what Dean could see. "Can I take you out to the car? Cas is here and he can drive while you sit with me in the backseat, ok? And I can doctor you up at my place, ok, just like I used to."

Sam sniffled and nodded. "Thank you."

"Course, Sammy. Come on." Dean put his arm protectively around his brother and led him out to the car.

"Just a second, Sammy." Dean opened the trunk to retrieve the blanket he and Cas kept on hand there and laid it across the backseat; he didn't particularly want to be scrubbing Sam's blood off the backseat of Cas' luxury car. "Here you go, can you get in alright?"

Sam nodded again and slowly clambered into the back of the car, and Dean followed suit.

"Cas, is it ok if you drive?" Dean put a hand on his boyfriend's shoulder.

"Yeah, babe, of course." As Cas walked around to the driver's seat and started the car, Dean turned to Sam, who was shivering next to him.

"Hey, little brother, you wanna lay down? You can put your head on my lap."

"Yeah, Dee. Thank you."

Dean blushed at the nickname, grateful it was dark. He'd never admit it, but he loved when his Sammy called him that, made him feel loved and like they were kids again. Sam settled in his lap, Dean stroking his hair and cooing at him while they drove back to his place. He knew he was treating his younger brother like a kid—for fuck's sake, the boy was legal now—but Sam had always gotten like this when he got hurt, and Dean was more than willing to indulge him.

When they got back to Dean and Cas' apartment, Dean helped Sam up the stairs and then laid him on the couch as soon as they were inside, Cas off searching for their scattered first-aid supplies.

"Ok, Sammy, tell me where it all hurts."

"Everywhere, Dean, shit." Sam tried to smile but cringed as it stretched the cuts on his face. Dean smiled kindly back and patted the boy's hand.

"I know, baby boy, but you've gotta tell me where it's bad so we can get you all fixed up."

"I know, Dean." Sam wiped a few more tears from his eyes before pointing to his temple. "Here."

"I can see that."

"And my arm. It's not broken, but it's twisted Dean, it's really sore."

"Anything else?"

"My stomach, but that's just cause it got hit. And my ribs, Dee, they hurt like hell."

Dean's eyes widened. "Are you having trouble breathing? Sammy, does it hurt to breathe?"

Sam shook his head. "No, not really, they're just really, really sore. But not as bad as when he cracked one that one time. 'S just bruised, I think."

Dean sighed and ran his fingers through his brother's hair. "Shit, Sammy. I'm sorry. I'm so sorry I wasn't there."

Sam's eyes grew and he shook his head. "No, Dean, please, don't apologize. You didn't need to be there. 'S not your fault, I promise."

"Mmmkay, Sammy." Dean leaned over to kiss his brother's head as Cas returned with supplies.

"How can I help, Dean?"

"Shit, Cas, you're amazing, you've already done so much-."

"Dean." Cas gave Dean a pointed but soft look. "Tell me what to do."

"Maybe just some ice for Sam—that ok, Sammy?"

"Yeah, Dean. Thank you, Cas."

"Of course." Cas and Sam had never really had the opportunity to get to know one another; Dean couldn't exactly take Cas home to meet his father, and even though Sam never objected in the slightest to the time Dean spent with his boyfriend, for some reason he usually declined when Dean offered to take Sam out with him and Cas.

Dean started on Sam's face, cleaning the cut on Sam's temple first, gently wiping away the dried blood and dabbing antiseptic on it before using a couple butterfly bandages to close it up. He cleaned the rest of Sam's face next, taking his time, carefully dabbing at the blood and cuts. "Do you wanna talk about it?" he asked after a few minutes of silence.

"No, not right now. Sorry, Dean."

"Hey, hey, don't apologize. I understand. You just get better."

He had Sam lift up his shirt next, wrapping the bag of ice Cas had brought him in a dishtowel and making Sam keep it where it was swelling slightly. "What else do you need, Sammy?"

"I think…just a fuck-ton of Advil, and sleep. And maybe a bottle of whiskey." He grinned wearily up at Dean with his last request.

"Hilarious, Sammy." Dean rolled his eyes affectionately as he went to retrieve a glass of water and Advil from the kitchen. Cas met him worriedly at the counter.

"How is he?"

"He'll be alright. Pretty sure we've seen worse." Dean leaned into Cas' arms, allowing the older man to gently stroke his hair and back for a few moments. "Thank you so much, Cas, really. I know this must suck for you, but…shit, you're amazing." He pulled back and looked gratefully into Cas' eyes. "I love you."

Cas kissed Dean tenderly on the forehead. "It's no bother at all, love. And I love you too."

Dean walked back into the living room to see Sam staring at him with raised eyebrows.

"What?" He opened the bottle and tossed a few pills into his hand.

"You know, Dean, homosexual activity is a serious sin."

Dean turned sharply to his brother, who winked and then burst out laughing, then wincing.

"Sorry, Dee, I just had to."

"You're a dick, baby brother, you know that, right?"

"I know, Dean." Before swallowing the pills Dean handed him, Sam looked up at Dean and gave him the sweetest smile Dean had seen in a long time, and Dean damn near lost it. He loved his little brother to death, but shit if having him here living with him wasn't gonna be fucking hard.


End file.
